[time-nuts] Strange effect with C-Field change

Carl Walker wa1raj at arrl.net
Thu Mar 24 21:20:38 EST 2005

Just wanted to mention that I've been making C-field adjustments on my 
5061A for the
last few weeks while monitoring  its performance vs. the Z3801A. I've 
had quite a few
large ESD events after shuffling across the carpet and down the basement 
stairs where
the discharge went directly to the C-field knob / outer protective 
shield. I've not seen
any phase jumps I could account for in this way.

The '61A is also really well shielded internally - I'd be really 
surprised if there was any
interference to its internal circuitry with a low power device like a 
cordless phone or cell
phone. Even with connections to stuff you would expect could cause 
problems (like
a connection from the control voltage output BNC to a 3456 meter for 
monitoring) I've
found the '61A to be surprisingly stable even in RF fields (high power 
from 160 M
through 2 M) encountered near my station.

YMMV, as they say.

After spending a bit of time tweaking it is quite amazing how well one 
of these older
units will perform - with the typical caveats about fairly stable 
ambient temperature
and other environmental factors. Parts in 10E-13 seem readily attainable 
- and I've
been impressed with the re-trace after powering the Cs tube down for a 
couple days
and then restarting. Not too shabby for the price.


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